Here's some of what Pop Up Businesses for Dummies has to say about Agile:
The simple idea behind the agile philosophy is that it's more important to get something up and running so that you can test and refine it with real people using it instead of planning it to the finest detail before launching it. If you plan for too long, you may be too late, you may be making something nobody actually wants or you may find that your competitors have got there first.
Key to the agile way of working is the idea of developing things that respond to the needs of people using it, rather than just the needs anticipated by the planners and designers.
The agile philosophy is a styleof working that you can apply to all sorts of discipplines. It's especially good for creating pop ups because pop ups are often planned and delivered in a short time and need a degree of flexibility.
The agile methodology is nothing clever, by the way. Every cafe is agile, serving the type of cake its customers want and brewing the blend of coffee that most of its customers want to drink!
Remember, though, that agile is still a form of business planning, and isn't an excuse for not planning! As the old business cliche has it, if you fail to plan, you plan to fail.